Rotating tube-straightening machine



April 8, 1958 R M. s-rlKELEATHlI-:R 2,829,593

ROTATING TUBE-STRAIGHTENING MACHINE Filed May 4, 1955 5 Sheets-Sheet 2 5Sheets-Sheet 3 R. M. STIKELEATHER ROTATING TUBE-STRAIGHTENING vMACHINE,April 8, 1958` Filed May 4, 1955 April 8, 1958 R. M. snm-:LEATHER2,829,698

ROTATING TUBE-STRAIGHTENING MACHINE 5 Sheets-Sheet 4 Filed May 4, 1955April 8, 1958 R. M. snm-:LEATHER 2,829,698

ROTATING TUBE-STRAIGHTENING MACHINE 5 Sheets-Sheet 5 Filed May 4, 1.955

162082223024: 30.581455 Msf'efeag dfndey United States Patent O ROTATINGTUBE-STRAIGHTENING MACHINE Robert M. Stikeleather, Holbrook, Mass.

Application May 4, 1955, Serial No. 505,998

4 Claims. (Cl. 153-100) This invention relates to tube straighteningmachines, and relates more particularly to machines for straighteningtubes for supply to finning machines.

A widely used type of heat exchanger for heating or cooling air or othergases is a hollow metal tube through which a heat exchange liquid iscirculated, and having a metal ribbon wound spirally on its externalsurface. Such ribbons on such tubes are usually referred to as tins Mycopending application, Serial No. 464,388, led October 24, 1954, nowPatent No. 2,799,389, granted July 16, 1957 discloses a nning machinefor winding such ribbons spirally on tubes to -form fins.

The tubes on which such ribbons are wound may be copper tubes of, sayoutside diameter, and are usually supplied in 20 lengths by a tubemanufacturer. Such short tubes not only involve intermittent operationof a iinning machine at short intervals with increased handling andoperating expense, but frequently the lengths of finned tubes which aredesired are not 20' lengths but may be longer or shorter than 20lengths. If longer, tubes must be spliced together. If shorter, cut olfportions are wasted.

Tubing manufacturers supply coiled tubes in boxes for use by plumbersand others, the lengths of such coiled tubes being 450. This inventionmakes use of such coiled .tubes to supply long straight tubing to anning machine, reducing the cost of the tubing, and reducing the cost ofiinning ythe tubing.

In one embodiment of this invention, the top of a box containing acoiled tube is removed, and the upper end of the tube is passed over arelatively large diameter reel having a horizontal rotary axis. Therelatively small radius curvature of the coiled tube is removed by thereel which also changes the direction of the tube and lines it up with acaterpillar type conveyor which moves the tube into a tube straightenercomprising a rotary tapered roll which ilexes the Itube back and forthfor` straightening and hardening it. A second caterpillar type conveyortakes the straightened and hardened tubing from the straightener, andsupplies it into a straight, long pipe or xtrough which stores a longlength of straight tubing. Two or more of such storage pipes areprovided closely together and parallel to each other.` A iinning machineis located alongside the tube straightener, and draws a straight tubefrom one of the storage pipes, and finsit while the straighteningmachine supplies another length of straight tubing into another storagepipe. An embodiment of this invention in actual operation straightensand stores a 450 length of straight tubing which enables a finningmachine to operate continuously for forty minutes, the nned tubing,while moving, being cut olf at the outlet side of the finning machine toprovide the desired lengths of nned tubing.

An object of this invention is to provide long straight tubes for use ina firming machine.

tubing for use in a nning machine.

. reel.

,. Nice Another object of this invention is to provide an improved tubestraightening machine.

This invention will now be described with reference to the annexeddrawings, of which:

Fig. 1 is a diagrammatic plan view of an embodiment of the invention inwhich a straightening machine straightens tubing taken from a coil,previously straightened tubing being shown supplied to a inning machine;

Fig. 2 is a side elevation of a reel arranged to remove a large part ofthe curl from coiled tubing, and to supply the partially straightenedtubing to a straightening machine;

Fig. 3 is a plan view looking downwardly upon Fig. 2;

Fig. 4 is a side elevation of the tube straightening ma'- chine;

Fig 5 is an end View of one of the conveyors of Fig. 4;

Fig. 6 is an enlarged side View, partially in section, of the rolls ofFig. 4, and their supports;

Fig. 7 is a plan view of Fig. 6;

Fig. 8 is a sectional view along the line 8-8 0f Fig. 7;

Fig. 9 is a sectional view along the line 9--9 of Fig. 6;

Fig. 10 is a sectional view along the line 10-10 of Fig. 11

Fig. 1l is a fractional side elevation of one end of one of theconveyors of Ithe straightening machine;

Fig. 12 is an end view of one of the sprockets of Fig. ll, and

Fig. 13 is a side elevation, partially in section, of another embodimentof a tube straightener that can be used to replace the one shown byFigs. 6-8. i

Referring first to Figs. 2 and 3, coiled tubing 15 is supplied by atubing manufacturer in a. rectangular wooden box 16. The top of the boxis removed, and the box is placed under a tube guide consisting of alower ring 17 joined by tubular legs to a smaller upper ring 19,therings being concentric with vertical axis. A relatively largediameter reel 20 has a horizontally extending shaft supported inbearings 21 on structural pipes 22 which are supported by verticallyextending structural pipes 23 which are connected by a brace 24 to aframe 25. A roller 26 is supported on the pipes 22 for guiding tubingfrom the coil 15 onto the reel. A roller 27 is supported on the pipes 22diametrically opposite the roller 26 for causing the tubing to followthe outline of the A third roller 28 is supported by the pipe 23 underand spaced from the reel, and serves to guide the tubing leaving thereel into the guides 30 on the frame 25.

The lower ring 17 of the tube guide above the box 16 is supported by thepipe 31 from the frame 25..

A tube straightening machine consisting of an incom- `ing caterpillartype conveyor 35, a tube straightener 36, and an outgoing caterpillartype conveyor 37 are supported on the `frame 25, with the inlet end ofthe conveyor` 35 located adjacent the tube guides 30.

The conveyors 35 and 37 are similar and each has an upper endless trackconsisting of spaced apart metal blocks 38 connected together by links39, and meshed with sprockets 40 at the opposite ends of the track,teeth 41 on the sprockets entering the spaces between blocks 38. Theblocks 38 in their outer surfaces have recesses 42 curved in circulararcs to fit `the tubing 15. Each yof the conveyors 35 and 37 also has alower track consisting of the blocks 45 connected together by links 46and meshed with teeth 48 on sprockets 47 at the oppositeends of thetrack. The blocks 45 in their outer surfaces have recesses 49 curved incircular arcs to fit the tubing 15.

An fOilite bearing plate 50 contacts the inner surfaces of the blocks 38in the lower pass of each upper track, and asimilar plate 51 contactsthe inner surfaces of the blocks 45 in the upper pass of each lowertrack, below and in alignment with the plate 50. Bolts 52 pass throughthe plates 50 and 51, and have coiled springs 53 around their lowerportions between nuts 54 and the lower plate, causing the blocks in thelower pass of the upper track and the blocks in the upper pass of thelower track to gripthe tubing with their recessed outer surfaces.

The shaft 55 of the inner sprocket 47 of the conveyor 37 is driventhrough sprockets and a chain 56 by a speed reducing lgear box 57 whichis driven by an electric motor 59. The shaft 60 of the inner sprocket 40of the conveyor 37 is driven by a gear 61 meshed with a gear 62 on theshaft 55y whereby the upper and lower tracks of the conveyor 37 aredriven together. The inner sprocket 47 of the conveyor 35 has a shaft 63with a sprocket driven by a chain 65 which is meshed with a sprocket 66on the shaft 55.v The inner sprocket 40 of the conveyor 35 has a shaft67 with a gear thereon which is not illus trated but which is similar tothe gear 61, which is meshed with a gear which is not illustrated butwhich is similar to gear 62, on the shaft 63 of the inner sprocket 47 ofthe conveyor 35, whereby the upper and lower tracks of the conveyor 35are driven together. The conveyor 35 is driven from the conveyor 37 bythe chain 65.

The tube straightener 36 which is located between thel conveyors 35 and37, comprises a pair of end members 70 to which the side plates 90 areattached by machine screws 91. The plates 90 have recessed or groovedportions shaped to provide with the inner surfaces of the members 70,passages in which blocks 74 are slidably positioned. The shaft 7S of atapered roll 76 is journalled in the blocks 74 which are attached tostraps 81 by machine screws 82, spacers 83 being placed between theblocks and straps. The straps 81 extend across the plates 90 and areattached thereto by the machine screws 80. Blocks 71 are also slidablypositioned in the passages formcd by grooves in the plates 90 and theinner surfaces of the members 70, and have journalled therein the shaft72 of a cylindrical roll 73. The blocks 71 are attached to straps 77 bymachine screws 78, spacers 79 being placed between the straps 77 andblocks 71. The straps 77 extend across and are attached to the plates 90by the machine screws 83. The plates 90 are attached to the end members70 by machine screws 91.

The outer portions 85 of the members 70 are formed as cylindricalbearing surfaces within the bearings S6, one of the end portions 85having a pulley 87 attached thereto which is driven through a belt 88 byan electric motor 89.

The spacers 83 are thicker than the spacers 79 and thereby space theshaft 75 of the tapered roll 76 nearer the rotary axis of thestraightener 36 than the shaft 72 of the cylindrical roll 73. The rolls76 and 73 are spaced apart at their nearest portions a distance slightlyless than the diameter of 'a tube 15 to be straightened. The taperedroll 76 is so located that it exes a tube 15 back and forth as it isrotated around the axis of the tube, the tube being squeezed between therolls 73 and 76 and being, therefore, hardened. Spacers having differentthicknesses are provided for varying the degree of tube exing andsqueezing, and also for the handling of tubes having differentdiameters.

A pair of relatively small plates 97 are bolted by machine screws 98 tothe mid portions of the outer surfaces of the plates 90, and haveportions 92 which extend through openings 93 in the plates 90 and formjournals for the shafts 95 of the tube backing-up rolls 94 which contactopposite sides of the tube 15 in its flexed position as shown by Figs.6-8.

A pair of tubes 96 extend around the tube 15 just short of where itenters and leaves the spaces between the rolls 73 and 76, and havebell-mouth inner portions 84 which are shaped to follow the curvature ofthe tube 15 where it starts to bend through being exed by the roll 76,and where it starts to straighten on leaving the rolls 73 and 76. Thebell-mouths support the tube and prevent it from buckling.

As the tube is flexed back and forth, all curl and other irregularitiesare removed so that the tube is straight when it enters the outgoingconveyor 37.

A straight tube on leaving the conveyor 37 enters one of the straightstorage pipes or troughs 99 shown by Fig. 1. While the straighteningmachine is supplying a straight tube into one of the pipes or troughs99, a previously straightened tube is being drawn from the other storagepipe or trough 99 by a nning machine 100 which is located alongside ofand close to the tube straightening machine. The pipes or troughs 99 areon opposite sides of and slightly spaced from a line extend ing midwaybetween the fnning and straightening ma chines. The slight temporarybend given the tube asA it enters and leaves a storage pipe is of noconsequencel as the spring action of the hardened tube causes such:temporary bends to straighten out.

Fig. 13 illustrates another tube exing and hardening device which can beused instead of the one shown by Figs. 6-8. In this embodiment, insteadof using bell mouthed tubes to follow the curvature of a tube 15 at thestart and end of its flexing, tapered rolls which are shaped andpositioned to follow such curvature, and oppositely positionedcylindrical rolls are used. Another difference is that the cylindricalroll opposite the tapered flexing roll is omitted. Advantages of thisembodiment are that there is less sliding friction, and additional tubehardening.

The tapered roll 76 for flexing the tube 15 is retained but itsco-operating cylindrical roll 73 is omitted. The bell mouths 84 are alsoomitted, and are replaced by tapered rolls 101 which are shaped andlocated to contact the tube where its exing starts and ends as describedin the foregoing in connection with the bell mouths 84. The taperedrolls 101 have opposite them cylindrical rolls 102 which contact thetube 15 opposite where it is contacted by the rolls 101. The adjacentclosest surfaces of the rolls 101 and 102 are closer together than thediameter of a tube 15 whereby the tube is squeezed between these rollsand thereby hardened.

The inner ends of the shafts of the rolls 101 are journalled in blocks103 and their outer ends are journalled in blocks 105 which blocks areslidably fitted in guideways in plates V104. The shaft of the taperedroll 76 is journalled in blocks 105A which arealso slidably tted inguideways in the plates 104. The inner ends of the shafts of thecylindrical rolls 102 are journalled in blocks 106 which are slidablytted in other guideways in the plates 104, and their outer ends arejournalled in blocks 107 which are slidably fitted in guideways formedby the inner surfaces of the end members 108 and recesses or grooves inthe plates 104. The blocks in which the shafts of the rolls arejournalled are held in place by machine screws 109 extending throughstraps 110 into plates 104. One of the end members 108 has a bearingportion 112 of reduced diameter in bearing 113, and has a pulley 114 onits outer end, this pulley being driven by the belt 88 of Fig. 4.

The tube straightening and hardening structure of Fig. 13 was found toreduce the sliding friction of a tube to be straightened and hardened,and the use of the tubes 101 and 102 instead of the bell mouths providedadditional squeezing and hardening of the tube.

Summary of operation In operation, the conveyors 35 and 37 draw a tube15 from the coil in the box 16, through the guides 17 and 19, over thereel 20, and through the guides 30 into the conveyor 35 so that the tubeis properly lined-up for movement through the straightening machine. Theflexing of the tube in the straightening device removes the curl fromthe tube and otherwise straightens it. The tube is hardened by thesqueezing so that it has sufficient spring tension to cause it to.remain straight during further handling.

The tinning machine 100 removes a previously straightened tube 15 fromanother storage pipe or trough 99 during the straightening of anothertube, and places a spiral fin 115 thereon.

The invention is not, of course, limited to the exact apparatus andarrangement of apparatus illustrated and described herein sincemodiiications thereof may be suggested by those skilled in the art,without departure from the essence of the invention.

What is claimed is:

l. A tube straightening machine comprising a support having similar,aligned, cylindrical passages at its tube entering and leaving ends forguiding a tube into and out of said support, said support having anopening between and aligned with said passages, the axes of said openingand passages being in alignment, means for rotating said support aboutsaid axes, means for moving a tube to be straightened through saidpassages and opening, a tube flexing roll in said opening, said rollbeing journalled for rotation in said support about the axis of saidroll and about the axis of said opening, said axis of said roll beingspaced from and parallel to said axis of said opening, said roll havinga tapered surface, the surface of said roll at its largest diameterextending a distance towards said axis of said opening less than theradius of said passages whereby the tube to be straightened is tlexed bythe rotation of said roll about said axis of said opening during therotation of said support, and a pair of tube backing-up rolls spacedapart a distance equal to the diameter of said passages and journalledfor rotation in said support about said axis of said opening, saidbacking-up rolls having axes equally spaced from said axis of said exingroll and extending parallel to said axis of said ilexing roll, astraight line extending through said axes of said opening and saidflexing roll being perpendicular to a straight line extending throughsaid axes of said backing-up rolls.

2. A tube straightening machine as claimed in claim 1 in which a pair ofspaced-apart hardening rolls is provided in said opening between saidtube entering end of said support and said exing roll, said hardeningrolls being journalled for rotation in said support` about said axis ofsaid opening, one of said hardening rolls being tapered, the spacingbetween the closest adjacent surfaces of said hardening rolls beingsmaller than said diameter of said passages.

3. A tube straightening machine as claimed in claim 2 in which a secondpair of hardening rolls is provided in said opening between said tubeleaving end of said support and said ilexing roll, said rolls of saidsecond pair being journalled for rotation in said support. about saidaxis of said opening, one of said rolls of said second pair beingtapered, the spacing between the closest adjacent surfaces of said rollsof said second pair being smaller than said diameter of said passages.

4. A tube straightening machine as claimed in claim 1 in which a pair ofspaced-apart hardening rolls is provided in said opening between saidtube leaving end of said support and said exing roll, said hardeningrolls being journalled for rotation in said support about said axis ofsaid opening, one of said hardening rolls being tapered, the spacingbetween the closest adjacent surfaces of said hardening rolls beingsmaller than said diameter of said passages.

References Cited in the file of this patent UNITED STATES PATENTS'518,403 Haas Apr. 17, 1894 602,931 Batey Apr. 26, 1898 1,538,325 HigginsMay 19, 1925 1,936,679 Leech Nov. 28, 1933

